Controlled angle ripper attachment

Claim 1

THE COMBINATION WITH A TRACTOR HAVING A PAIR OF VERTICALLY DISPOSED RIGID COLUMNS AT ONE END THEREOF, A PAIR OF LEVERS PIVOTALLY CONNECTED TO SAID TRACTOR AT THE LOWER ENDS OF SAID COLUMNS, A TOOL-SUPPORTING BAR OF POLYGONAL CROSS SECTION RIGIDLY JOINED TO THE EXTREMITIES OF SAID LEVERS FOR PIVOTAL MOVEMENT BETWEEN UPPER AND LOWER POSITIONS RELATIVE TO SAID TRACTOR, AND PISTON AND CYLINDER MEANS INTERCONNECTING THE UPPER ENDS OF SAID COLUMNS AND SAID LEVERS TO EFFECT RAISING AND LOWERING OF SAID LEVERS AND SAID TOOL-SUPPORTING BAR, OF A RIPPER ATTACHMENT COMPRISING: (A) A CLEVIS STRUCTURE HAVING U-SHAPED END PORTIONS AT RIGHT ANGLES TO EACH OTHER, ONE END PORTION DEFINING A HORIZONTAL SLOT TO RECEIVE SAID TOOL-SUPPORTING BAR, THE OTHER END PORTION DEFINING A VERTICAL SLOT TO RECEIVE A RIPPER BAR; (B) MEANS FOR REMOVABLY SECURING SAID CLEVIS STRUCTURE TO SAID SUPPORTING BAR; (C) A RIPPER BAR VERTICALLY DISPOSED IN SAID VERTICAL SLOT; (D) PIVOT MEANS EXTENDING HORIZONTALLY THROUGH SAID RIPPER BAR AND CLEVIS STRUCTURE, PIVOTALLY CONNECTING SAID RIPPER BAR THEREIN FOR MOVEMENT ABOUT AN AXIS PARALLEL WITH THE PIVOTAL AXIS OF SAID LEVERS; (E) A LINK PIVOTALLY CONNECTED TO THE UPPER END OF SAID RIPPER BAR AND WITH AT LEAST ONE OF SAID COLUMNS, TO FORM, WITH THE PIVOTAL AXIS OF SAID PIVOT MEANS AND THE PIVOTAL AXIS OF SAID LEVERS, A PARALLELOGRAM; (F) AND A RIPPER TOOTH AT THE LOWER END OF SAID RIPPER BAR.